Pneumatic-despatch-tube apparatus.



E. A. FORDYGE. PNEUMATIG DESPATGH TUBE APPARATUS.

APPLICATION FILED MAY 18, 1907.

Patented Dec. 16, 1913.

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.B. A. FORDYOE. PNEUMATIC DESPATOH TUBE APPARATUS. APPLICATION IiLED MAY 18, 1907.

COLUMBIA PLANOGRAPH co., WASHINGTON. D. c.

Patented Dec. 16, 1913..

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E. A. PORDYGE.

PNEUMATIC DBSPATOH TUBE APPARATUS.

APPLICATION FILED MAY 18, 1907.

Patented Dec. 16, 1913.

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EDMOND A. FORDYCE, 0F BOSTON, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AMERICAN PNEUMATIC SERVICE COMPANY, OF BOSTON, MASSACHU- SETTS, A CORPORATION OF DELAWARE.

PNEUMATIO-DESPATCH-TUBE APPARATUS.

LOSTAML Specification of Letters Patent.

Patented Dec. 16, 1913.

To all whom it may concern:

. Be it known that I, EDMOND A. FoRDYoE, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Pneumatic-Despatch-Tube Apparatus, of which the following is a specification.

My invention relates to improvements in pneumatic despatch tube apparatus and particularly to that class wherein a vacuum is maintained and carriers are transmitted therethrough by the admission of atmospheric pressure.

The objects of my invention are to simplify and render more positive the mechanism for controlling the admission of air to the system for driving carriers and to time the admission of air to the interval necessary for the proper transmission and delivery of the carriers.

In the accompanying drawings which illustrate a construction embodying my invention, Figure 1 is a diagrammatic view of a pneumatic tube system showing the location of the controlling and timing mechanism. Fig. 2 is an enlarged sectional view of the bell mouth or transmission tube at the central station and the controlling mechanism connected therewith showing the parts in normal closed position. Fig. 3 is a similar view to Fig. 2 showing the position of the parts upon the insertion of a carrier into the bell mouth at the central station for transmission to the sub-station.

Like letters of reference refer to like parts throughout the several views:

C is the central station or cashiers desk and S is a sub-station or sales counter.

A is a tube for the transmission of carriers from the central station C to the substation S and connects the bell mouth B with the ordinary downward discharge terminal D at the'sub-station.

E is a transmission tube for the return of carriers and connects the terminal D at the sub-station with the terminal F at the central station. Carriers are inserted in the tube E at the sub-station S through an ordinary inlet valve G. The valve D controls the delivery opening of the terminal D at the sub-station and the valve F controls the delivery opening of the terminal F at the central station.

H is a vacuum tube connecting the terminal F with the drum 1.

J is a diaphragm casing attached to the tube A at the bell mouth 13. Mounted in the casing J is a diaphragm J attached to the diaphragm stem J 2 to the upper end of which is attached a gate-valve J secured thereto by a cotter pin J The valve J 3 is normally seated across the transmission tube A by means of a spring J mounted over the lower end of the diaphragm stem J beneath the diaphragm J. The lower end of the diaphragm stem J 2 is reciprocally mounted in the diaphragm casing J. The lower chamber j of the diaphragm casing J is connected with the vacuum tube H by a tube J A by-pass J 7 connects the upper with the lower chamber of the diaphragm casing J and is restricted and graduated by a timing screw J The upper chamber j is connected with the passage J 9 having an opening J adapted to admit atmospheric pressure to the chamber This opening J is controlled by a pilot valve K pivoted at K and held normally closed by the spring K K is a resistance plate located in the bell mouth B of the tube A and is adapted upon the insertion of a carrier into said bell mouth B to open the valve K. This plate K also acts to retard the passage of air into the tube A when the valve J 3 is open. L is a smaller diaphragm casinghaving a diaphragm L mounted therein and secured to the stem L The chamber L above the diaphragm L is in communication with the vacuum in the tube A through the openings L The diaphragm L i adapted to be held normally in the position shown in Fig. 2 by the action of the vacuum within the tube A. Then this vacuum is broken, the diaphragm is permitted to drop by gravity restricted by the exhaust of air from beneath said diaphragm through a passage L graduated and controlled by the timing screw L. After the diaphragm L has dropped a certain distance the lower end of the stem L is adapted to engage and open a pilot valve M pivoted at M and admit air into the passage M which communicates with the diaphragm chamber j. The valve M is normally held closed by gravity.

The operation is as follows: The cashier at the central station C desiring to despatch a carrier to the sub-station S inserts the carrier into the bell mouth B (Fig. The resistance plate K being depressed opens the valve K admitting air through the passage J to the diaphragm chamber j breaking the vacuum maintained therein through the restricted passage J and tube J The spring J gives the valve J a bias or tendeney for its closed position but the preponderance of vacuum in the lower chamber y" draws the diaphragm J downward against the tension of the spring J 5 opening the valve J permitting the passage of the carrier and the admission of air into the tube A. After the carrier has passed over the resistance plate K said plate is returned to normal or upright position as shown in Fig. 2 closing the valve K and shutting off the admission of air to the diaphragm chamber The carrier is now driven through the tube A by the air admitted into the bell mouth B around the plate K in the meantime, the air is being exhausted from the chamber through the passage J allowing the spring J 5 to gradually close the gate valveJ shutting off the supply of air to the tube A. In the meantime, the carrier has discharged through the valve D at the sub-station S, the closing of the gate-valve J being timed by the adjustment of the timing screw J to the interval. necessary to secure the positive delivery of the carrier.

In despatching a carrier from the sub station S to the central station C, the inlet valve G is opened, the carrier inserted into the tube 11; the opening of the valve G destroys the vacuum in the tube A and the chamber L permitting the diaphragm L to drop by gravity. After the diaphragm L has dropped a predetermined distance, the stem L engages and operates the lever M to open the valve M and admit air (see dotted lines Fig. 2) through passage M to the upper diaphragm chamber 7' breaking the vacuum therein as heretofore described and causing the opening of the gate valve J to admit air through the bell mouth B. The inlet valve G having been closed, the air entering around the resistance plate K drives the carrier through the tube E toward the central station C; in the meantime, the resistance to the air offered by the plate K causes a slight vacuum with in the transmission tube A and chamber L lifting, the diaphragm L and permitting the valveM to close by gravity shutting off the admission of air to the diaphragm chamber j. The gate valve J is now permitted to be closed gradually in the manner heretofore described and the carrier discharges through the valveF at the central station C. The fluctuation of the vacuum normally main tained in the transit tubes. A and E caused by the momentary discharge of carriers through the delivery valves D and F is not of suficient duration to allow the diaphragm L to drop sufiiciently to operate and open the valve M thereby causing a repetition of the operation.

Having thus described the nature of my invention and set forth a construction embodying the same, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A pneumatic despatch tube apparatus, having, in combination, a transit tube provided at one end with a single inlet to admit carriers for transmission and also outside air to propel the carriers, means through which air is exhausted from the transit tube, a valve, mounted for substantially unreregardless of the disposition of a carrier inserted in said inlet preparatory for transit,

said valve controlling the inlet of the transit tube, and pneumatic mechanism operating normally to hold said valve closed and actuated by a fluctuation of pressure to open said valve to admit a carrier and also the outside air to propel such carrier.

2. A pneumatic despatch tube apparatus, having, in combination, a transit tube provided at one end with an inlet to admit outside air to propel carriers, means through which air is exhausted from the transit tube, a single normally closed valve controlling the inlet of the transit tube, pneumatic mechanism actuated by a fluctuation of pressure to open said valve to admit outside air through the inlet into the transit tube, carrier-introduction means at the other end of the transit tube operating when opened to cause a variation of pressure in the transit tube, and an auxiliary pneumatic mecha nism actuated by a variation of pressure in the transit tube to cause a fluctuation of pressure in the valve operating mechanism to actuate the latter to open the valve to admit outside air to the transit tube, said auxiliary mechanism including means for insuring that said pneumatic mechanism shall be rendered operative by said variation in pressure in the transit tube only when said variation has persisted a determined and material period of time.

3. A pneumatic despatch tube apparatus, having, in combination, a transit tube through which carriers are transmitted, a central or sending station into which carriers are inserted for transmission, means through which air is exhausted from said tube, a valve at said central or sending station normally closing the carrier inletand adapted to open to admit air into said tube for driving carriers, a casing communicating with said tube, valve opening means mounted in said casing and connected with said valve, mechanism for rendering operative said valve opening means through an excessive fluctuation of pressure in the tube which persists for a determined and material period of time, said valve opening means being so rendered operative by said mechanism only by such a persisting fluctuation, and means through which air may be eX- hausted from both sides of said valve operating means.

4. A pneumatic despatch tube apparatus, having, in combination, a transit tube through which carriers are transmitted, a central or sending station into which carriers are inserted for transmission, means through which air is exhausted from said tube, a valve at said central or sending station normally closing the carrier inlet and adapted to open to admit air into said tube for driving carriers, a casing communicating with said tube, valve opening means mounted in said casing and connected with said valve, mechanism for rendering operative said valve opening means through a fluctuation of pressure in the tube which persists for a determined and material period of time, said valve opening means being so rendered operative by said mechanism only by such a persisting fluctuation, means through which the air pressure may be equalized upon both sides of said valve opening means, and co-acting means for timing the closure of the valve.

5. A pneumatic despatch tube apparatus, having, in combination, a transit tube through which carriers are transmitted, a central or sending station into which carriers are inserted for transmission, means through which air is exhausted from said tube, a reciprocably mounted gate at said central or sending station normally closing said tube and adapted to open to admit air into said tube for driving carriers, a casing communicating with said tube, gate opening means mounted in said casing adapted to open said gate through an effective fluctuation of pressure in the tube, means whereby the fiuid pressure in the casing may be equalized on both sides of the gate opening means and maintained at a pressure lower than atmospheric, and means operated by the insertion of a carrier for permitting an increase of pressure on one side of said diaphragm to operate the same to open the gate.

6. A pneumatic despatch tube apparatus, having, in combination, a transit tube through which carriers are transmitted, a central or sending station into which carriers are inserted for transmission, means through which air is exhausted from said tube, a valve at said central or sending station normally closing said tube and adapted to open to admit air into said tube for driving carriers, a casing communicating with said tube, valve opening means mounted in said casing, means for rendering said latter means operative to open said valve after the lapse of a determined and material period of time following the development of a fluctuation of pressure in said tube, means whereby the fluid pressure in the casing may be equalized on both sides of the valve opening means, and co-acting means for timing the closure of said valve.

7 A pneumatic despatch tube apparatus, having, in combination, a central station, a substation, a transit tube from the outside to the sub-station, a return transit tube from the sub-station to the central station connected with the first tube to receive air therefrom and provided with a carrier entrance, a gate closing the carrier entrance to the return transit tube, an air valve for the transit tube, a device for opening said valve, means whereby the fluid pressure may be equalized on both sides of the valve opening device and maintained at a pressure lower than atmospheric, means operated by the increase of pressure in the transit tube caused by the opening of the gate at the substation to permit an increase of pressure on one side of said valve opening device to operate the same to open the valve to the transit tube, and co-acting means for controlling the action of said last mentioned means, to insure that it shall operate in manner aforesaid only when said increase in pressure in the transit tube is other than a mere momentary one.

8. A pneumatic despatch tube apparatus, having, in combination, a central station, a sub-station, a transit tube from the central to the sub-station, a return transit tube from the sub-station to the central station connected with the first tube to receive air therefrom and provided with a carrier entrance, a gate closing the carrier entrance to the return transit tube, an air valve for the transit tube, means for opening said valve, means operated by the insertion of a carrier at the central station for permitting an increase of pressure on one side of said valve opening means to operate the same to open the valve, and means operated by the increase of pressure in the transit tube caused by the opening of the gate at the substation operating to permit an effective increase of pressure on one side of said diaphragm to operate the same to open the valve to the transit tube, said last mentioned means including an auxiliary valve, means for actuating said auxiliary valve and means for timing said actuating means.

9. A pneumatic despatch tube apparatus which comprises a transit tube, means for automatically establishing a carrier-propelling flow of air through said tube upon the occurrence of a change in pressure in said tube which persist-s for a substantially determined period of time, said means including an air current controlling device having a bias for a determined position, means for moving said device from said position and name to this specificationin the presence of timing means for controlling sald movlng two subscrlblng wltnesses, thls tenth day of means, and a second timing means for (3011- May A. D. 1907. i

trolling the return of said device to said de- EDMOND A. FORDYCE. 5 termined position When displaced therefrom -Witnesses:

by said moving means. MARY Gr. SMITH,

In testimony whereof, I have signed my LOUIS Gr. BARTLETT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

